The hyper-injunction goes a step further. Mr Hemming told the Commons that the order, which was obtained at the High Court in 2006, prevents an individual from saying that paint used in water tanks on passenger ships could break down and release potentially toxic chemicals.

It specifically bars the person from discussing the case with "members of Parliament, journalists and lawyers", along with the US coastguard and any ship owners, and also forbids any speculation linking chemicals in the paint with the illness of any individuals.

It says: "The defendant must not communicate to the third parties any speculation that the illness of any individual (including without limitation the collapse of H) was, has been or will be brought out by the chemical composition or the chemicals present in the coating of the potable water tanks."

According to Mr Hemming, the individual was given a two-week suspended sentence after talking to a lawyer about whether he would take up the case on a no-win, no-fee basis. Mr Hemming said: "What we have, therefore, is passenger vessels trundling around the world with potentially toxic substances being released into the tanks. One of those who worked on the tanks collapsed as a result.

"From a health and safety point of view, we want to think that the water we are drinking is safe and that it will not cause health problems. The difficulty in this case is that we do not know.

"What we do know is that corporations used the massive force of the law to gag an individual and truss him up so much that he could not really challenge the process." There are growing concerns that super-injunctions are being used by corporations and wealthy individuals to suppress information.

Niri Shan, the head of media law at the legal firm Taylor Wessing, said: "I have never seen a super-injunction that bans someone from speaking to an MP. One of the fundamental rights that you have as a citizen is that you should be able to speak to your MP, particularly if it relates to matters of public concern.

"This is the development of privacy law through the courts as opposed to Parliament legislating on it. It is deeply concerning, and undermines freedom of speech." In 2009 Paul Farrelly, a Labour MP, took similar steps to Mr Hemming to disclose the existence of a super-injunction obtained by the oil firm Trafigura, which banned reporting of toxic waste being dumped in the Ivory Coast.

There have been several super-injunctions obtained by well known figures in recent months.

Last month, a sportsman known to have cheated on his partner with two women won an appeal to remain anonymous when the judge said the fact he had conducted a previous affair would make it easier for people to work out the nature of the allegations.